Depends on what it does for you. For example, if monitor is 1080p, I wouldn't go that way.
But $500 is $50 lower than any price on pcpartpicker, so for "right now", that's a good buy
looking at what card delivers most bang for the buck ....At 1440p ....
The reference cards stack up as follows in total performance per techpowerup @ 1440p
1080 Ti = 95
1080 = 74
1070 = 59
Add in the typical overclocking and ....
1080 Ti = 95 x 1.15 = 109
1080 = 74 x 1.16 = 86
1070 = 59 x 1.13 = 67
Add in current pricing .... and we see that at $500, that 1080 delivers the most performance per dollar. At the $550 price every where else, the Ti is more attractive (assuming you can use all that power) but at $500, grab it while ya can
1080 Ti =...